Within a harbour region, or between different harbours and working places it is frequently necessary to transport heavy cargoes, for instance steel constructions, machine parts, containers, etc. When transferring the goods to a barge or vessel there arise great difficulties as to the trimming of the barge, because the barge tends to sink and also heels over. Generally, the goods are brought aboard by means of cranes. Only a few harbours are provided with feasible big lifting devices.
A great advantage would be obtained if the heavy cargoes instead could be moved in the horizontal plane, directly onto the barge or vessel without any expensive lifting arrangements. No satisfactory and simple method of maintaining the cargo supporting deck of the barge or vessel horizontally at the level of the embankment plane when the cargo is transferred is, however, available. Such operation would involve intense and time consuming trimming of the barge.
Additionally, there might be substantial and fast water level variations.